Cost-effectiveness evaluation of abiraterone in the treatment of patients with castration-resistant prostate cancer who previously received docetaxel.

Abstract

e15107 Background: Treatment with abiraterone improves overall survival (OS), time to prostate-specific antigen progression and radiologic progression-free survival when added to prednisone and best supportive care in patients with advanced castrate-resistant prostate cancer (CRPC) who previously received docetaxel. Little is known about its cost-effectiveness in the United States. Methods: In order to raise awareness of pharmacoeconomics concepts and inform policy-makers in the US, this study aimed to assess the cost-effectiveness of abiraterone in the treatment of advanced CRPC patients, from a payer perspective. We created a decision-analytical model using clinical data from the pivotal phase III trial: COU-AA-301. Health utilities were derived from the available literature. Costs for drug acquisition, physician visits and laboratory tests were obtained from the Center for Medicare Services Drug Payment Table and Physician Fee Schedule and are represented in 2011 US dollars. Life-years saved (LY), Quality-adjusted life years (QALY) and Incremental Cost Effectiveness Ratio (ICER) were calculated using updated survival data presented at the 2011 ASCO meeting. Other main scenarios used the original median survival data published in the New England Journal of Medicine article and adjusted median OS to represent an overall survival hazard ratio of .66. Sensitivity analyses were performed using the confidence intervals for median OS in the pivotal study as well as by halving or doubling all other model inputs. No discounting was used due to the short time-horizon. Results: Abiraterone added 0.38 LY and 0.30 QALY with an incremental cost of $39,320 and therefore a cost of $102,600/LY and an ICER of $129,000/QALY. The main drivers of the model were drug acquisition cost, median OS, and health utility values. The results of the model were robust in different scenarios and sensitivity analyses. Conclusions: Using commonly accepted willingness-to-pay thresholds, such as those suggested by the World Health Organization, treatment of patients with advanced CRPC patients with abiraterone is likely to be cost-effective in the US.